Life After Being a Pathology Department Chair: Issues and Opportunities.

Although there is a considerable literature on transition of faculty members to the position of department chair, there is a dearth of publications about transitioning from the chair to other activities including retirement. The Association of Pathology Chairs senior fellows (all of whom are former chairs of academic departments of pathology) made this topic a focus of discussion at the Association of Pathology Chairs 2016 Annual Meeting. Of the 33 senior fellows engaged in this discussion, following their time as chairs, a small majority (18) transitioned to other administrative posts within or outside the university, while the others either returned to the active faculty (7) or retired (8). The motivating factors and influences for transitioning from the chair were probed along with the processes used in executing the transition, such as the development of transition plans. The reasons for selecting the specific type of postchair activity were also investigated. There was extraordinary diversity in the type of post-chair activities pursued. To our knowledge, no other medical specialty has examined these issues, which may be potentially relevant for the career planning of active chairs

How Children Used to Work

Discusses the changing role of children in the United States from 1800-1970, focusing on the increasing conflict between child rearing and other activities of parents, the curtailment of child labor, and the decreasing importance of children as a source of old-age financial support for their parents

Lithopanspermia in Star Forming Clusters

This paper considers the lithopanspermia hypothesis in star forming groups and clusters, where the chances of biological material spreading from one solar system to another is greatly enhanced (relative to the field) due to the close proximity of the systems and lower relative velocities. These effects more than compensate for the reduced time spent in such crowded environments. This paper uses 300,000 Monte Carlo scattering calculations to determine the cross sections for rocks to be captured by binaries and provides fitting formulae for other applications. We assess the odds of transfer as a function of the ejection speed and number of members in the birth aggregate. The odds of any given ejected meteroid being recaptured by another solar system are relatively low. Because the number of ejected rocks per system can be large, virtually all solar systems are likely to share rocky ejecta with all of the other solar systems in their birth cluster. The number of ejected rocks that carry living microorganisms is much smaller and less certain, but we estimate that several million rocks can be ejected from a biologically active solar system. For typical birth environments, the capture of life bearing rocks is expected to occur 10 -- 16,000 times per cluster (under favorable conditions), depending on the ejection speeds. Only a small fraction of the captured rocks impact the surfaces of terrestrial planets, so that only a few lithopanspermia events are expected (per cluster).Comment: 27 pages including 5 figures; accepted to Astrobiolog

Life After Being a Pathology Department Chair II: Lessons Learned.

The 2016 Association of Pathology Chairs annual meeting featured a discussion group of Association of Pathology Chairs senior fellows (former chairs of academic departments of pathology who have remained active in Association of Pathology Chairs) that focused on how they decided to transition from the chair, how they prepared for such transition, and what they did after the transition. At the 2017 annual meeting, the senior fellows (encompassing 481 years of chair service) discussed lessons they learned from service as chair. These lessons included preparation for the chairship, what they would have done differently as chair, critical factors for success as chair, factors associated with failures, stress reduction techniques for themselves and for their faculty and staff, mechanisms for dealing with and avoiding problems, and the satisfaction they derived from their service as chair. It is reasonable to assume that these lessons may be representative of those learned by chairs of other specialties as well as by higher-level academic administrators such as deans, vice presidents, and chief executive officers. Although the environment for serving as a department chair has been changing dramatically, many of the lessons learned by former chairs are still valuable for current chairs of any length of tenure

Stem and progenitor cells: Origins, phenotypes, lineage commitments, and transdifferentiations

Multipotent stem cells are clonal cells that self-renew as well as differentiate to regenerate adult tissues. Whereas stem cells and their fates are known by unique genetic marker studies, the fate and function of these cells are best studied by their prospective isolation. This review is about the properties of various highly purified tissue-specific multipotent stem cells and purified oligolineage progenitors. We contend that unless the stem or progenitor cells in question have been purified to near homogeneity, one cannot know whether their generation of expected (or unexpected) progeny is a property of a known cell type. It is interesting that in the hematopoietic system the only long-term self-renewing cells in the stem and progenitors pool are the hematopoietic stem cells. This fact is discussed in the context of normal and leukemic hematopoiesis

Higher spin Dirac operators between spaces of simplicial monogenics in two vector variables

The higher spin Dirac operator Q_{k,l} acting on functions taking values in an irreducible representation space for Spin(m) with highest weight (k+1/2,l+1/2,1/2,...,1/2), with k, l in N and k>= l, is constructed. The structure of the kernel space containing homogeneous polynomial solutions is then also studied

Research Reports from the Programme for Belize Archaeological Project, Volume Seven

Table of Contents : Background and Introduction to the 2012 Season of the Programme for Belize Archaeological Project / by Fred Valdez, Jr. and Grant Aylesworth (p.1-6) -- The Architecture and Environs of Structure 3: 2012 Season / by Debora Trein (p.7-34) -- Report of the 2012 Excavations at the South Ballcourt of La Milpa, Operation A6 / by David Chatelain (p.35-38) -- Overview of the 2012 La Milpa Archaeological Field Season / by Brandon s. Lewis, Yoav Me-Bar, Scott Guzman, and Leon de Santillan (p.39-54) -- Several Burials from La Milpa, LM4 in NW Belize / by Stacy Drake (p.55-58) -- Report in the 2012 Excavations at Hun Tun: Operation 5 / by Robyn L. Dodge (p.59-68) -- Research Results of the 2012 Field Season: Excavations at the Tapir Group of the Medicinal Trail Site / by David M. Hyde (p.67-90) -- Mapping Medicinal Trail: A Summary from 2004 to 2012 / by Jeff Brewer, David M. Hyde, and Michael Stowe (p.91-112) -- The 2012 Season of Survey and Excavation at La Milpa North / by Eric J. Heller (p.113-130) -- Preliminary Investigations at RB 71: The 2012 Field Season / by Nicole DeFrancisco and Cory Stevenson (p.131-140) -- Preliminary Report on the 2012 Field Season at Maax Na and Bolsa Verde, Belize / by Eleanor M. King and Leslie C. Shaw (p.141-154) -- Summary Report of Field Investigations at the Site of Dos Hombres, Summer 2012 Season / by Rissa M. Trachman and Jacob A. Canterbury (p.155-164) -- Field Investigations at Chawak But’o’ob: Preliminary Overview of the 2012 Season / Stan Walling (p.165-178) -- Ancient Maya Land Use and Today’s Environment: A Multidisciplinary Research Program / by Nicholas Brokaw (p.179-186) -- Summary Report of the 2012 Obsidian Provenance Project for PfBAP / by Walter Beckwith (p.187-188) -- Application of Low-Field Magnetic Susceptibility to Plaster Floors in Excavation Profiles at Maya Sites in the Three Rivers Region, Belize / by Michael Brennan (p.189)Texas Archeological Research Laborator

The Howe dual pair in Hermitean Clifford analysis

Clifford analysis offers a higher dimensional function theory studying the null solutions of the rotation invariant, vector valued, first order Dirac operator ∂. In the more recent branch Hermitean Clifford analysis, this rotational invariance has been broken by introducing a complex structure J on Euclidean space and a corresponding second Dirac operator ∂J , leading to the system of equations ∂f = 0 = ∂Jf, expressing so-called Hermitean monogenicity. The invariance of this system is reduced to the unitary group. In this paper we show that this choice of equations is fully justified. Indeed, constructing the Howe dual for the action of the unitary group on the space of all spinor valued polynomials, the generators of the resulting Lie superalgebra reveal the natural set of equations to be considered in thiscontext, which exactly coincide with the chosen ones

Discrete Rotational Symmetry and Quantum Key Distribution Protocols

We study the role of discrete rotational symmetry in quantum key distribution by generalizing the well-known Bennett-Brassard 1984 (BB84) and Scarani-Acin-Ribordy-Gisin 2004 (SARG04) protocols. We observe that discrete rotational symmetry results in the protocol's invariance to continuous rotations, thus leading to a simplified relation between bit and phase error rates and consequently a straightforward security proof.Comment: 7 page